Carbon steel elbow is resistant to air, steam, water and other weak corrosive media and acid, alkali, salt and other corrosive corrosive medium steel, also known as stainless acid resistant steel. In the power, mine, metallurgy and other industries of carbon steel, the delivery and output of materials are transported by close range and high pressure. The pipeline is subjected to considerable pressure and is subjected to very serious wear. A single material pipe is difficult to meet the requirements of this working condition, especially the elbow, considering its safety and use. Life expectancy focuses on improving toughness, impact resistance and wear resistance of piping lining. At the same time, we should also consider the overall strength of pipes and elbow. In practical applications, the steel that is often eroded by weak corrosion medium is often called stainless steel stamping elbow, and the steel which is resistant to chemical corrosion is called acid resistant steel. Because of the difference in chemical composition between the two, the former does not necessarily resist chemical erosion, while the latter is generally rusty. The chrome stainless steel elbow also sets mechanical strength and high extensibility in one body and is easy to make parts. It can meet the needs of architects and structural designers.
The forming technology of carbon steel bending head: first welding a polygon ring shell with a polygon or a closed multi prismatic shell at both ends. After the internal pressure is filled with pressure medium, the internal pressure is applied, and the cross section is gradually turned from a polygon to a circle under internal pressure. Finally, it becomes a circular ring shell. According to the needs, a circular ring shell can be cut into 4 90 bending heads or 6 60 bending heads or other specifications. This process is suitable for the inner diameter ratio of the bending head and the elbow to more than 1. 5 of the large elbow of any specification is the ideal way to make carbon steel elbow at present.
Technical specification: this technology is suitable for manufacturing working pressure less than 10MPa, elbow inner diameter D 125mm, elbow diameter D and elbow inner diameter D ratio D/d 1. The elbow diameter of 5 is not limited. For example, a large elbow with an elbow inner diameter of 12m and an elbow diameter greater than 60m can be manufactured.
Applications: pipeline systems in petroleum, natural gas, chemical industry, hydropower, construction and boilers.
In order to avoid the erosion of carbon steel elbow because of heating, the welding current should not be too large, 20% less than the carbon steel electrode, the arc can not be too long, the interlayer is fast cold, and the narrow welding path is suitable. Because the carbon steel elbow is more hardened after welding, it is easy to produce cracks. If the same type of stamping elbow is used for welding, it must be preheated at temperatures above 300 and 700 degrees slow after welding. If the weldment cannot be heat treated after welding, carbon steel elbow electrode should be used.
5 properties of carbon steel elbow:
1, wear resistance: the Al2O3 content in the inner lining ceramic layer of carbon steel elbow is more than 90% and the microhardness is HV1000–1800, so it has very high wear resistance, and its wear resistance is ten times higher than that of the medium carbon steel after quenching, which is better than tungsten carbide.
2. Corrosion resistant ceramics are neutral materials. Their chemical function is not messy. It has excellent corrosion resistance and acid resistance. It can resist all kinds of inorganic acids, organic acids, organic solvents and so on. The corrosion resistance is ten times more than that of stainless steel.
3. Heat resistance is excellent, and it can withstand temperatures above 2000 degrees. It can work in the range of -50 to 900 degrees Celsius.
4. Easy to weld: carbon steel elbow can be connected by welding the outer steel pipe.
5. Transportation and installation convenience: carbon steel elbow is relatively light weight, easy to transport and install. The ceramic lining composite elbow can be welded, flanged, and flexible fast joints. The installation is very convenient.
